Paper stretch tester



Nov. 1, 1932. H. KOESTER Q 1,385,209

PAPER STRETCH TESTER I Filed July 1, 1930 2 Sheets-Shee 1 llllulllINVENTOR Herman Koesfer ATTORN'EY Nov. 1, 1932. K ESTER 1,885,209 IPAPER'STRETCH TESTER Filed July l, 1930 2 Sheets-Shee 7 u Fm m\'INVENTOR Her/flan K0657?! FIG. 2

ATTORNEY Patented Nov. 1, 1932 UNITED STA HERMAN KOESTEB', OIWATIERBUBY, CONNECTICUT, ASSIGNQB, TO THE BRISTOL COMPANY, OF WATEBBUBY,CONNECTICUT,

a conrom'rronor CONNECTICUT PAPER STRETCH TESTER Application died July1, 1980. Serial No. 465,088.

'The invention relates to measuring apparatus, and more particularly toapparatus for the determination of stretch in paper under difi'erentatmospheric conditions, more especially with respect to relative humidty. The invention has for its object the provlsion ,of a simple andconveniently operated tester device of this nature whereby com aratlvetests as to the extent of stretch ma e made simultaneously upon aplurality 0 samples; and it has for a further object to prov de suchtesting apparatus with means for ma ntainin predeterminedconditions ofrelatlve humidity and temperature, as well as for varying the same.

In carrying out the invention, a plurallty of paper strips ofuniiormlength and width are designed to be rigidly secured at one end, while atthe other andvfree end they are arranged to be placed under aliketension and to connect with suitable indicating members whereby anychange in length due to stretching of the paper material willbferegistered so that a comparison maybe had; among the various samplesunder test. plurality of test strips to this end is convenientlyarranged within a closed chamber through which suitably conditioned airis arranged to be circulated; and this air may be varied both as totemperature and relative humidity, but is automatically maintainedduring a test period. Therefore, in setting up difierent atmosphericconditions within the chamber and obtaining readings of the stretchunder the various conditions established, curves may be plottedtherefrom to show clearly the behavior of the different samples.

The nature of the invent-ion, however, will best be understood whendescribed in connection with the accompanying drawings, in

which: I

Fig. 1 is a front elevation of the stretch tester apparatus withportions broken away.

Fig. 2 is a side elevation thereof,

Figs. 3 and 4 are respectively a rag ,or recording arm 21 withadjustable-countermentary front elevation and a fragmentary sideelevation on an enlarged scale of the indicating mechanism and papersample support, together with actuatlng connections between a sample andits indicating device.

Referring to the drawings, 10 designates a suitable casing or cabinet inthe interior of which is a. panel 11 designed to have mounted thereon aplurality of test strips 12, the panel, for example, being hinged toswing outwardly to afi'ord convenient access in securing the stripsthereon for test. These strips consist of the diflerent paper samples tobe tested which are cut for this purpose to equal lengths and are of thesame width throughout.

At the uppzr end of a sample, the same is arranged to clamped to a baror stationary support 13 as by means of clamping blocks 14 to attach astrip firmly to the panel. At its 5 lower end, a strip is securedbetween two block members 15 to which is secured, also.

a downwardly extending rod or wire 16; and a guide bar 17 is positionedimmediately behind the various blocks=15 to prevent inward 7 swing andtwist of a strip and rod. The latter is, further, suitably guidedv as inpassing through guide members 18 and'19 which extend outwardly from thepanel.

Moreover, at its lower end a rod carries a tensioning weight 20 ofsufiicient mass to hold the paper samples reasonably taut and to exertthe desired degree of tension thereon, as well as to counterbalance apointer of multiplying mechanism to be operated so through the extensionof the paper sample under the applied tension.

This multiplying mechanism comprises a pointer element which may be anindicating weight 22, which is required for the first adjustmentin orderto counterbalance the associated arts so that the only tension influenceexerte on a paper strip 12 would be that due to the tensioning weight 20and of exactly the same value for all of the strips. Each recording arm,furthermore, is fulcrumed to the panel as at 23, while its outer end isadapted to move over a graduated scale on a scale plate 24 alsocarriedon the panel. At its inner end, the lever is linked by a wire 25 withthe pointer. or rod 16 as in being connected to an arm 26 attached tothe latter.

It will be understood that each of the rods 16 is thus provided with anindicating pointer, the attachment of the actuating connections thereforbeing progressively lower along the different rods and the differentgraduated scales being correspondingly arranged upon the scale plate 24.Thus, as the individual paper strips 12 stretch differently under theequal tensions applied thereto, the extent of each stretch will beindicated upon a corresponding scale and readings may behad of thecomparative stretches under the same atmospheric conditions.

The latter may conveniently be provided and maintained within the casing10 by a suitable temperature regulator device 30 and a humidityregulator device 31 with motoroperated air valve control device 32. Theformer operates to control the heat developed by an electrical heatingelement, as a resistor member 33 mounted within the casing, and thelatter devices to control the degree of moisture discharged as sprayfrom a nozzle 34 into the said chamber, all of which is well understoodand forms no particular part of the presentinvention. The regulatorinstruments 30 and 31 aforesaid are of any well-known or special designand may conveniently be mounted upon a board or wall 35 exteriorly ofthe casing 10 and to which the latter may also be secured, as indicated.

A dry-bulb thermometer 36 is mounted within the cabinet for determiningthe operation of the combined temperature-control andtemperature-indicating device 30; and a fan 37 and driving motortherefor is arranged to draw air from the interior of" the said casing10 over a wet-bulb thermometer 38, preferably located exteriorly of thecasing, for determining the operation of the combined humidity-controland humidity-indicating device 31. An inverted water jar 39 is arrangedin the usual manner to supply water to wick pan or trough 40 associatedwith the bulb of thermometer 38 for maintaining moist a wick 41 aboutthe same. The said fan 37 is designed, moreover, to cause a suitablecirculation of the atmosphere through the casing 10 as by means of aduct or flue 42 connected with the top and bottom of ,the casing, asindicated. A damper 43 with actuating handle 44 may be provided in --thecirculating-duct 42 for controlling the flow therethrough.

" The atmospheric conditions within the casing 10 may, therefore, bemaintained substantlally constant during a period of test,

it being understood that the casing is to be closed at the. front duringsuch test, for example by a transparent cover or door'45, so that theindications afforded by the different pointers 21 may be visible. Inorder to efiect a change in atmospheric conditions within the casing 10,it is necessary merely to correspondingly set the temperature-controldevice 30 or the humidity-control device 31, or both. These will thenautomatically provide the desired conditions in the usual and wellknownmanner. It will be understood, also, that those portions of theapparatus such as the strip supports, mountings for the recording arms,the scale plate, etc., which would affect the accuracy of thereadingsbecause of a change in length at different temperatures are tobe constructed of zero temperature-expansion coeflicient material.

I claim:

1. A paper-stretch tester, comprising a. fixed support, means to suspendtherefrom one end of a. plurality of test strips, tensioning membersattachable to the opposite ends of the individual strips, and respectivemeasuring means connected with the respective tensioning members andactuated by movement thereof. I

2. A paper-stretch tester, comprlsing a. closed test chamber'and meansto maintaln predetermined atmospheric conditions therein, means tosuspend from one end a plurality of test strips in said chamber,tensioning members attachable to the opposite ends of the individualstrip, and a pluralitypf measuring means secured to the respectivetensioning members at progressively lower points and actuated thereby.

3. A paper-stretch tester, comprlslngb a closed test chamber, a panelswi nga ly mounted therein, means to suspend from said panel at one enda plurality of test strips, tensioning members attachable to theopposite ends of the individual strips, bearing means on said panel forguiding the tensioning members for vertical movement resulting from thestretch of a strlp, a scalebearing member movable with the panel, andrespective measuring means plvotally mounted on said panel, actuated bythe movement of a tensioning member and cooperating w1th thescale-bearing member.

4. A paper-stretch tester, compr slng a closed test chamber, a panelswlngably mount-ed therein, clamp members earned by the panel forsuspendingat one end a plurality of test strips, tensionlng members andrespective clamps associated therewith for securing a tensioning memberto the opposite end of a strip, bearing means on said panel for guidingthe tensioning members for vertical movement resulting from the stretchof a strip, a scale-bearing member movable with the panel, andrespective measuring mean pivotally mounted on said panel, actu-

